Wigs

As with many group photos the clowns show up in the back row. Here they are sporting a number of wigs.

Don't Give Up the Ship Boys

A mule drawn parade float. This was constructed by a machine gun company at Camp Cody, New Mexico.

Messines

A German supply depot at Messines two months before the Battle of Messines (1917).

300 Meters From the Frenchmen

A frontline German trench. If the note on the back is to be believed it is only 300 meters to the opposing French trench.

Infanterie-Regiment Nr. 126 Großherzog Friedrich von Baden

This card was sent shortly after the regiment entered the line in the sector near Ville-sur-Tourbe in January of 1917.

Baker and March

On the left is Newton Diehl Baker, Jr., Secretary of War from 1916 to 1921. On the right is General Peyton Conway March. This picture was taken between March and June of 1917 when March had the rank of Brigadier General. He was promoted to Major General in August.

Another Army Tent Fire

"This is what is left of Corp Hummels tent after the fire. The X is me"
The tents here had electric lights as well as a stove so there were at least two possible sources of the fire.

Camp Dix, New Jersey

There is a draft registration card for Byron Silence Walton of Philadelphia, PA. His middle name is first written as Silas. That is then crossed out and corrected with Silence. He is also listed as an Infantry Captain in the Officers Reserve Corps after the war.
A faint pencil note at the top of the card states he "Will soon follow this card".

German POW at Brocton

A German prisoner at the POW Camp in Brocton, England. This was a British Army training facility that was turned into a POW Camp in 1917.

Ein Gruß aus England

These six German soldiers are posing with an unexploded 38mm shell that they have written "Ein Gruß aus England" which translates to "Greetings from England". The faint writing at the bottom places them at Minacourt in 1917.

Scher Studio

The soldier has the collar disc for the US National Army. That would date the photo from the end of 1917 to the beginning of 1918.

Cathedral of St. Quentin

Three German posing before the ruins of the Cathedral of St. Quentin. This would appear to be shortly after the cathedral caught fire in August 1917.

Battery A,1st Section

A group of artillerymen with the Wisconsin National Guard at Camp Douglas.

Mykulyntsi

A group of Germans resting in Mykulyntsi (Mikulińce) after crossing the Seret River.

Wilhelm Stienbuck

A card from Wilhelm Stienbuck while serving in Roeselare, Belgium. The larger sign indicates he was part of the paying office for the woodworker's union (Holzarbeiter Verband Zahlstelle: Roulers). The smaller one reads Flandern 1917.

Update:
I just scanned this card which was a few cards down the line in the box. It is also to Dora Stienbuck from the same soldier. His first name here is a bit more legible and seems to be Wilhelnye. That does not come up in any search engine as a name. Regardless what his first name may be, Herr Stienbuck did serve at least two years. The earlier card was postmarked in April of 1915 and the other in March of 1917.

In 1915 the 18th Reserve Division was in the Lassigny area until October.

Horse in a Hole

Whatever is happening here took place on March 10th, 1917 if the date on the back is correct.

Feldlazarett 92

The Germans while occupying Cambrai, France used Groupe Scolaire Paul Bert as a Field Hospital. The building is in use today as an elementary school.

Lichtblinkgerät

A group of signalers in a well tended camp. Someone had taken the time to encircle the fern with a stick path. They are posed with two signal lamps.

French POWs

Some French prisoners in front of their German captors. Curiously there are no weapons to be seen. Perhaps the Germans are patients of the infirmary which they are all standing in front of.  

German Position on the Western Front

A German soldier casually reading in a rough trench.